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biofilm growth Articles

The biofilm process is a process which uses a biofilm for the purposes of filtration, bioremediation or barrier formation. A biofilm is a complex and heterogeneous matrix of microorganisms attatched to and growing on a surface. Biofilms are most often found on solid substrates that are exposed ...

Biomass accumulation is a load-limiting factor in the operation of biofilters used for air pollution control. As the biofilm thickens, portions at the base are no longer exposed to contaminants and oxygen and, thus, provide no treatment. Smaller pores are filled with biomass so that air no longer flows into them. As airflow paths are restricted, air may be prevented from reaching some pores even ...

Silver-containing phosphate-based glasses were found to reduce the growth of Pseudomonas aeruginosa and Staphylococcus aureus biofilms, which are leading causes of nosocomial infections. The rates of glass degradation (1.27 to 1.41 µg·mm–2·h–1) and the corresponding silver release were found to account for the variation in biofilm growth ...

Sewer biofilms play an important role in the biotransformation of substances for methane and sulfide emission in sewer networks. The dynamic flows and the particular shear stress in sewers are the key factors determining the growth of the sewer biofilm. In this work, the development of sewer biofilm with varying shear stress is specifically investigated to gain a comprehensive understanding of ...

Abstract Biofilms (slime) can form on virtually every nonshedding surface, in a nonsterile aqueous environment i.e. anywhere where a water source is present; such as cooling/heating systems, swimming areas and in drinking water purification. These Biofilms can cause a myriad of problems including; harbouring harmful bacteria such as Legionella, inducing corrosion, and reducing ...

Summary Biological fouling on membranes is a major problem in desalination and water purification plants. Oceanographers and limnologists have found that most marine and fresh waters are full of microscopic Transparent Exopolymer Particles, otherwise known as TEP. In this article, aquatic microbiologist Tom Berman and Filtration Specialist Marina Holenberg (Amiad Filtration Systems, Amiad, ...

Heterogeneous biofilms may arise because of non-uniform biofilm growth. When considering multiple-scale problems involving biofilms, a direct simulation of the flow in the heterogeneous biofilm is not tractable. This calls for an averaged description of the flow and transport in such heterogeneous biofilms. This paper presents a theoretical derivation of the transport equations in such ...

Accumulations and spatial and dynamic variations of biofilms in the media of a biotrickling filter were simulated using mathematical models for Volatile Organic Compound (VOC) removal. Toluene was selected as the model VOC. Effects of toluene concentration and gas Empty Bed Contact Time (EBCT) on VOC removal were also investigated. Results showed that biofilm thickness increased with increased ...

The research was aimed at assessing changes in the number of bacteria and evaluating biofilm formation in groundwater collected from public wells, both aspects directly related to the methods of household storage. In the research, water collected from Cretaceous aquifer wells in Toruń (Poland) was stored in a refrigerator and at room temperature. Microbiological parameters of the water ...

The good composition and activity of biofilms are very important for successful operation and control of fixed-film biological reactors employed in liquid effluents treatment. During the last decade, microsensors have been applied to study microbial ecology. These sensors could provide information regarding the microbial activity concerning nitrification and denitrification that occur inside ...

Sponge carrier media provide a large surface area for biofilm support; however, little information is known about how to model their dual nature as a moving bed and as porous media. To investigate the interaction of mass transfer and detachment with bio-clogging, a novel biofilm model framework was built based on individual-based modelling, and hydrodynamics were modelled using the lattice ...

A simplified fixed biofilm model was developed to formulate the relationship between the substrate concentrations at both the entry and exit, at the biofilm–liquid interface and at the biofilm attached surface along with average substrate flux in the biofilm, substrate flux at the biofilm–liquid interface and effective biofilm thickness. The model considered the substrate mass transport ...

Abstract Within the lifetime of most reverse osmosis (RO) systems some fouling will adversely affect membrane performance.One of the major foulants identified on lead membranes during a decade of membrane autopsy at the Genesys Membrane laboratory is biological fouling (biofouling). All raw water sources contain microorganisms such as algae, bacteria and fungi. They also contain ...

Microbial indicators such as heterotrophic bacteria, total coliforms, and Escherichia coli in naturally developed riverbed biofilms were investigated. Pebbles covered with natural biofilm were sampled directly from the riverbed at sampling stations ranging from the upstream region within a quasi-national park to the midstream in the urban district. Heterotrophic bacteria densities in biofilm ...

Bone related infectious diseases (including osteomyelitis and prosthesis infection) are of great concern to the medical world. These types of deep tissue infections involve biofilms and are frequently chronic and always painful. Biofilms are infections whereby bacteria form a robust colony protected by a sticky slime matrix from the body's immune system (or natural clearance) and are resistant to ...

Biofilm plays an important role in controlling the transport of colloids in a porous media. Biofilms are formed when micro-organisms come in contact with substrates, and are able to attach and grow with availability of nutrients. The microorganisms get embedded in a matrix of the substrate and extracellular polymeric substances which are responsible for the morphology, physico-chemical ...

The dynamic reactor behaviour of a nitrifying inverse turbulent bed reactor, operated at varying loading rate, was described with a one-dimensional two-step nitrification biofilm model. In contrast with conventional biofilm models, this model includes the competition between two genetically different populations of ammonia-oxidizing bacteria (AOB), besides nitrite-oxidizing bacteria (NOB). ...

Bacterial biofilms cause a number of serious problems for industrial fluid processing operations. Mechanical blockages, impedance of heat transfer processes and microbially induced corrosion result in billions of dollars of losses each year. In engineered systems, such as cooling water systems, food processing, and other industrial applications possible risk to public health and product spoilage ...

Flume experiments were conducted to investigate the distribution and composition of extracellular polymeric substances (EPS) in biofilms and the detachment mechanism of biofilms grown under different flow velocity conditions. The results of biofilm growth kinetics showed that the growth trends were coincident with the logistic growth model. The growth kinetics parameters reached their maximum ...

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